The invention relates to a device for metering out a flowable mass, especially a fat-containing mass for the production of confectionery products, for example to a nozzle for extruding the mass into a mold, the mass making its way through an inlet opening into a chamber, from which it can be extruded through an outlet opening by means of a plunger, and the plunger being assigned a rotary piston, which in one usage position shuts off the outlet opening and in a further usage position shuts off the inlet opening, which rotary piston has a recess.
Chocolate candies, for example, consist in many cases of a chocolate casing and a chosen filling and are today produced automatically in the industrial field by so-called one-shot technology. In this method, the chocolate is introduced into a mold through a single nozzle, for example through an annular duct, and, at the same time, a filling is introduced through an axial bore, the filling pressing the chocolate casing against the mold wall, so that a closed chocolate candy is produced from casing with filling by a single “shot”.
The corresponding substances for the casing and the filling are brought to the nozzles by means of pumps, a pump being respectively assigned to a nozzle on a nozzle bar. These rows of pumps are in turn connected to a single lifting bar, so that the lifting motion of the pump plungers is realized by the motion of the lifting bar. In the lifting bar are also seated rotary elements, which rotate the pump plunger respectively about 180°.
Arrangements of this type are described, for example, in DE 297 06 282 U1 and DE 199 34 106 A1. The flowable mass makes its way through an inlet opening into a metering chamber, which is formed by a part of the pump plunger being cut away parallel to the axis and being pierced in this region. This produces in the pump plunger a delimited cavity, between which and an inner wall of a pump a certain quantity of substance can be accommodated. As soon as the metering chamber, and a space between the floor of the cylinder chamber and the end face of the pump plunger, is filled with substance, the pump plunger is rotated about 180°, so that the cavity is assigned to an outlet opening. If the pump plunger is now plunged deeper into the cylinder chamber, then the space between the end face of the pump plunger and the floor of the cylinder chamber is reduced, so that the substance is forced out of this space into the cavity and a corresponding quantity of substance makes its way through the outlet opening.
The nearest prior art is constituted by DE 1 936 358, in which a valveless, continuously adjustable pump for the metering of liquids is described. With this, liquids can be metered for the treatment of textiles contaminated with fibers. To this end, two interconnected pistons are present in a pump cylinder, one of which has a metering function and the other of which performs an oscillatory motion. The pistons are provided on their front side with profiles, which are situated in one or more planes. In one piston there is a curved bore, which can selectively be connected to an inlet or outlet.
The object of the present invention is to improve the metering of the flowable mass and to facilitate the introduction of the flowable mass into the cylinder chamber and from the cylinder chamber, the flowable mass also being able to contain larger items.